A known mounting line for manufacturing plural kinds of mounting substrates in parallel is a mounting line including two substrate supply apparatuses which are parallelly arranged in a direction orthogonal to a conveyance direction of the substrate and supply mutually different kinds of substrates, a screen printing apparatus for receiving two kinds of substrates supplied from these two substrate supply apparatuses and performing screen printing on the substrates one by one, and a component mounting apparatus for receiving the substrate carried out by the screen printing apparatus in one substrate conveyance lane and mounting components in the substrate as disclosed in JP-A-2011-143640, for instance.